When I design or illustrate, the goal is to have my client say "I love it!" Collaboration is also so helpful; I've done some of my best work when I received plenty of feedback.
99.7% of my work is original. That is the advantage of being an illustrator, with keen design instincts. Most Saturdays in childhood, I hung around the art department of my Dad's printing company in Philadelphia while he worked. I'm sure I picked up a thing or two!